芦荟、无花果复合果汁饮料的研制

以芦荟、无花果为主要原料,加入白砂糖、柠檬酸和蜂蜜,研制出芦荟、无花果复合果汁饮料.采用正交试验和感观评定确定了产品的最佳配方和加工工艺.最佳配方为芦荟汁:无花果汁为4:6、白砂糖90g,L、柠檬酸2.Sg/L、蜂蜜10g/L.     

椿芽保鲜工艺研究

通过实验,对椿芽的护绿、保脆、保藏液汁液配比和杀菌条件探讨研究。结果表明,护绿最佳工艺为:含锌离子浓度300μg/mL、铜离子浓度500μg/mL的浸泡汁液,70℃浸泡温度和1h浸泡时间;保脆最佳工艺为含0.1%氯化钙、3.0%食盐的浸泡汁液,2h浸泡时间;保藏汁液最佳配比为0.1%醋酸、0.02%山梨酸钾、3.0%食盐、0.1%氯化钙和0.1%异Vc钠;最佳杀菌工艺为75℃杀菌40min。椿芽经上述处理后能长久的保持色泽、脆度和香味。     

芦荟加工过程中芦荟多糖变化研究

芦荟在加工过程中,芦荟多糖的含量不断变化,导致芦荟粉中的芦荟多糖含量较低.针对芦荟加工过程中芦荟多糖的变化,将芦荟加工工艺进行分析.结果表明:酶解工序和无机膜微滤工序对芦荟多糖下降的影响最大.故优化加工过程和工艺参数,芦荟粉中的芦荟多糖含量明显提高.     

芦荟纤维的练漂前处理

以白度和强力为指标,试验探讨了芦荟纤维的练漂工艺。优化的漂白工艺为:双氧水25 mL/L、硅酸钠5 g/L、渗透剂JFC 2 g/L、碳酸钠2 g/L、温度90℃、时间50 min、pH值11。经练漂处理后,纤维白度可提高到78.6,强力较原纤维下降了10.8%。     

响应面-频数法优化芦荟大黄素提取工艺

[目的] 确定芦荟大黄素提取的最佳工艺，对我国芦荟产业的发展具有重大意义。[方法] 在单因素的基础上，选取盐酸浓度、三氯化铁用量、反应时间3个因素，以芦荟粉为原材料，通过溶剂法提取分离芦荟苷，再通过三氯化铁氧化法，制备芦荟大黄素。采用二次通用旋转组合设计，以芦荟大黄素含量为评价指标，建立两因素与指标的回归模型，最后运用频数法得出最优工艺参数组合。[结果] 芦荟大黄素的提取的最优工艺参数为：盐酸浓度3.842～5.052 mol/L、氧化剂加入量21.245～30.695 g、保温时间7.736～8.954 h。[结论] 经实验验证，在此工艺条件下提取芦荟大黄素含量大于9.89，产品质量优良达到满意的效果，通过响应面-频数法，达到了优化的目的。     

生物法制备芦荟大黄素的研究

采用生物法,利用重组葡萄糖苷酶催化芦荟苷合成芦荟大黄素,通过单因素试验及均匀试验设计得到了合成芦荟大黄素的最佳工艺条件:反应时间4 h,酶浓度50 U/m L,叔丁醇∶水(v/v)=5∶5,反应温度43℃,p H值5.2.该工艺条件下芦荟大黄素转化率为92.18%.     

芦荟大黄素的超声辅助提取及其对HSC-T6细胞的抑制作用

研究芦荟皮中芦荟大黄素的超声辅助提取工艺及其对HSC-T6细胞生长的影响。在单因素试验基础上,利用响应面法优化芦荟大黄素的超声辅助提取工艺,并通过MTT增殖试验、Hoechst 33258荧光染色研究其对HSC-T6细胞生长的影响。结果显示,料液比、超声功率、超声时间对芦荟大黄素的提取率有显著影响,芦荟大黄素最佳超声辅助提取条件为:乙醇体积分数72%、液料比1∶33(g/m L),超声功率300 W、超声提取时间36 min,在此条件下芦荟皮芦荟大黄素提取率为1.44%。芦荟大黄素对HSC-T6增殖具有显著的抑制作用,在一定浓度范围内呈现一定的剂量时间效应关系,48 h半数抑制浓度IC50为35.85μg/m L。诱导HSC-T6细胞凋亡是芦荟大黄素抑制细胞生长的作用途径之一。     

芦荟纤维针织面料练漂工艺研究

文中对芦荟半空气层罗纹组织针织物的煮练工艺与效果进行了介绍与测试,并对其漂白工艺条件进行了单因素分析和正交优化实验。实验表明,在Na2CO3用量1 g/L、精练剂1 g/L、温度80℃、时间60 min条件下进行煮练,织物白度增加了2.1%,顶破强力下降了4.1%;4因素3水平的漂白工艺正交实验确定了优化后的漂白工艺为:双氧水25 mL/L、硅酸钠5 g/L、渗透剂JFC用量2 g/L、Na2CO3用量2 g/L、温度80℃、时间50 min、pH值11;采用优化的漂白工艺处理煮练后的芦荟半空气层罗纹针织物,织物白度有了明显的提高,且强力下降不多,不影响织物的后续加工和服用性能。     

基于模糊数学评价法优化低钠盐腌制即食红鱼片工艺

探究腌制料配比和加工工艺对即食红鱼片品质的影响,研发一种低钠盐腌制的即食红鱼片产品。以红鱼作为研究对象,模糊数学感官评价法为主要考察指标,利用质构、色差等技术,研究低钠盐腌制工艺和烘干油炸工艺对即食红鱼片品质的影响。确定的最佳腌制料配比：低钠盐6 g/100 g、白砂糖5 g/100 g、生抽3.0 g/100 g、料酒150 g/100 g、白醋2.0 g/100 g、碳酸氢钠0.6 g/100 g、辣椒面9 g/100 g,最佳的加工条件：烘干温度50 ℃、烘干时间3 h、油炸温度160 ℃、油炸时间3.0 min。该配方下得到的低钠盐腌制即食红鱼片色泽金黄,有嚼劲,咸淡适中。     

魔芋真空冷冻复合护色剂的选择

以新鲜魔芋为原料,研究了魔芋经护色剂处理后真空冷冻干燥过程。在单因素实验的基础上,对护色剂进行筛选,得出适合魔芋真空冷冻干燥的护色剂及添加量,以感官评定为评价指标,通过响应面优化护色剂配方。结果表明:魔芋真空冻干的护色剂最佳配比为:柠檬酸浓度为7.74g/L,L-半胱氨酸浓度为0.115g/L,抗坏血酸浓度为0.203g/L。在此试验条件下得到的魔芋色泽呈乳白色,感官品质良好。     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status